Support for py3

Support for py3

This patch provides support for py3 in the deployment host and the OPNFV
VM. Some extra changes will need to happen in the future when distros
disclose how they will react to the py2 expiration.

* virtualbmc version is upgraded to 1.5 because 1.3 is not compatible with
py3
* The dynamic inventory is slightly modified because it was using
functionality that changes in py3
* pip3 check is removed as Ansible now works with py3

deploy-scenario:k8-calico-nofeature
installer-type:osh

Change-Id: I34178ebc357b0a299c0017d6f9e596b815c77b3b
Signed-off-by: Manuel Buil <mbuil@suse.com>